The telencephalon (plural: telencephala or telencephalons) is the most anterior region of the primitive brain.
Together with the diencephalon, the telencephalon develops from the prosencephalon, the primitive forebrain .

The inferior boundaries of the telencephalon are found at the diencephalon and brainstem . Posteriorly the telencephalon is bordered by the cerebellum .

The telencephalon is composed of surface grey matter (the cerebral cortex) and underlying white matter, with deep masses of grey matter . The corpus callosum facilitates communication between the two hemispheres .

The telencephalon comprises:

Related pathology

Atelencephaly is a rare disorder that results when the ​derivatives of the telencephalon are absent or dysplastic.